CD19‐targeted chimeric antigen receptor (CAR)‐modified T (CAR‐T) cell immunotherapy has demonstrated impressive results in B‐cell malignancies, and CAR‐T cell therapies targeting other antigens are in development for other cancers. Cytokine release syndrome (CRS) and neurotoxicity can be life‐threatening in a subset of patients. The severity of CRS and neurotoxicity can be impacted by the disease burden, lymphodepletion regimen, and CAR‐T cell dose. Tocilizumab and corticosteroids have been used to manage these toxicities, enabling CD19 CAR‐T cells to be administered without obvious compromise in efficacy. Consensus criteria for grading and managing toxicities will facilitate the widespread application of this treatment modality.